The present invention relates generally to self-propelled forage harvesters and more particularly to an improved transfer chute which guides crop material between the cutterhead and blower units.
The well known agricultural practice of forage harvesting consists of comminuting either green or mature crop material into discrete particles and conveying them from the field to a storage silo where they undergo an acid fermentation to give them an agreeable flavor and to prevent spoilage. This operation, which is commonly referred to as an ensilage process, converts standing crop in the field to livestock feed, commonly referred to as silage.
An essential piece of farm machinery used for producing silage is the forage harvester which is adapted to gather crop material from the field, cut it into small particles and then convey the comminuted crop material to a temporary storage bin or wagon. Harvesters of this type can be either self-propelled or pulled by a tractor. Typically, forage harvesters include a rotary cutting mechanism having knives disposed in a generally cylindrical configuration with cutting edges peripherally exposed to cooperate with a fixed shear bar for cutting crop material as it is being passed across the shear bar. An optional perforated recutter screen is used under some conditions to reduce the size of cut crop material to an even further smaller dimension.
Forage harvesters are commonly provided with a blower to convey the cut crop to a wagon towed to the rear of the harvester for receiving the crop. In one well known prior art arrangement, comminuted crop material is transferred to the blower from the cutterhead via an auger system comprising side-by-side augers at right angles to the axis of the rotary cutter. Problems have been encountered in some instances with this type of mechanism when material accumulates unevenly along the augers and causes clogging. From a design standpoint, augers provide extra moving parts that are subject to wear and thereby reduce overall the reliability and servicability characteristics of the harvester. Furthermore, the use of augers increases the power requirements of forage harvesters, particularly in crop material having a high moisture content.
To overcome problems of this nature, many self-propelled forage harvesters have been designed with cutterheads which discharge material directly to the blower without intermediate conveying means. In these direct discharge machines, the blower unit receives material fed from the cutterhead directly to the fan blades which, in turn, convey the cut crop material upwardly through a spout and thence to a bin or wagon. For maximum effectiveness, the cutterhead and blower units in self-propelled harvesters are mounted in close proximity. This gives rise to problems when access to the blower and rear portions of the cutterhead becomes necessary for the purpose of service, inspection, repair, etc. To this end, some prior art forage harvesters provide access by pivotally mounting the blower or cutterhead about a vertical axis to swing the units relative to each other. In other instances, various parts or assemblies must be removed to gain access to the blower and, depending on the relationship of the various parts and assemblies on the unit, lengthy disassembly and reassembly operations can be required when access becomes necessary.